Synthesis and Functionalization of Copper-Doped Indium Phosphate Quantum Dots with Ratiometric Fluorescence

The doped quantum dots (QDs) that feature dual emission in one nanocrystal and long fluorescence lifetime have gained great interest in biosensing and bioimaging applications. In this work, we report the synthesis and functionalization of copper ion-doped indium phosphate (Cu:InP) QDs that exhibit simultaneous green InP emission and red Cu[Formula: see text] emission. The oil-soluble QDs were synthesized by adsorbing Cu[Formula: see text] onto InP core, followed by growing zinc selenide (ZnSe) shell via the successive ion layer adsorption reaction. During the synthesis, fluorescence ratiometry (and resultant multiple fluorescence colors) can be generated by changing either the dopant amount or the shell-growth time, but they act in a different manner: increasing the Cu[Formula: see text] amount results in quenched InP emission and oppositely improved Cu[Formula: see text] emission; the increase of shell-growth time leads to continuously improved Cu[Formula: see text] emission relative to constant InP emission. Further, functionalization of the oil-soluble Cu:InP QDs with dihydrolipoic acid-polyethylene glycol (DHLA-PEG) via ligand exchange produces the water-soluble and biocompatible dual-emission QDs. The PEGylated Cu:InP QDs present desirable charge neutrality and excellent thermal stability and photostability, thereby holding high potential in a diversity of biomedical applications.

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Determination of Trace Iron in Chinese Herbal Medicine Using CdS Quantum Dots as Fluorescence Probes

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.455-456.1195 ◽

2012 ◽

Vol 455-456 ◽

pp. 1195-1199

Author(s):

Yun Long Zeng ◽

Xia Fei Li ◽

Chun Ran Tang ◽

Hao Wen Huang ◽

Ya Jing Wang ◽

...

Keyword(s):

Quantum Dots ◽

Fluorescence Probe ◽

Copper Ion ◽

Water Soluble ◽

Fluorescence Probes ◽

Cds Quantum Dots ◽

Buffer Solution ◽

Green Protocol ◽

Quenching Method

A simple A green protocol for synthesis of high quality, water-soluble and biocompatible CdS QDs have been developed in aqueous solution with amylum as stabilizing agent. The QDs were characterized by AMF and spectral methods. A fluorescence quenching method was developed for determination of iron (ΙΙΙ) with water soluble CdS quantum dots (QDs) as fluorescence probe. In pH 8.5 boric acid–borax buffer solution, the QDs show a high selective to ferric ion. The common cations, such as Ca2+, Mg2+, Zn2+, Fe2+ et al, have no effect on interference but copper ion. The fluorescence intensity of the QDs decreased linearly with the iron (QDs ) concentration in the range of 200 μM to 60 nM with a detection limit of 20 nM. It has been applied to determinate of iron in Angelica, Astragalus, Shouwu, ligusticum wallichii and radix rehmanniae recen.

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Luminescence enhancement of colloidal quantum dots by strain compensation

MRS Proceedings ◽

10.1557/opl.2013.579 ◽

2013 ◽

Vol 1547 ◽

pp. 109-114

Author(s):

Y. Lu ◽

Y.Q. Zhang ◽

X. A. Cao

Keyword(s):

Quantum Dots ◽

Shell Growth ◽

Luminescent Properties ◽

Optical Quality ◽

X Ray Diffraction ◽

Cdse Qds ◽

Light Emitting ◽

Full Color ◽

Layer Adsorption ◽

Strain Compensation

ABSTRACTWe have investigated the effects of two different strain-relief bilayer shell structures on the luminescent properties of colloidal CdSe quantum dots (QDs). CdSe QDs with a strain-compensated ZnS/ZnCdS bilayer shell were synthesized using the successive ion layer adsorption and reaction technique and their crystallinity of was examined by X-ray diffraction. The QDs enjoyed the benefits of excellent exciton confinement by the ZnS intermediate shell and strain compensation by the ZnCdS outer shell. The resulting CdSe/ZnS/ZnCdS QDs exhibited 40% stronger photoluminescence and a smaller peak redshift upon shell growth compared to conventional CdSe/ZnCdS/ZnS core/shell/shell QDs with an intermediate lattice adaptor. CdSe/ZnS/ZnCdS QD light-emitting diodes (LEDs) had a luminance of 558 cd/m2 at 20 mA/cm2, 28% higher than that of CdSe/ZnCdS/ZnS QD-LEDs. The former also had better spectral purity. These results suggest that nanocrystal shells may be strain-engineered in a different way to achieve QDs of high crystalline and optical quality well suited for full-color display applications.

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Energy Transfer from Dual-Emission Manganese-Doped Quantum Dots to Graphene Oxide

The Journal of Physical Chemistry C ◽

10.1021/acs.jpcc.1c10367 ◽

2022 ◽

Author(s):

Ruixiang Wu ◽

Xiaoshuai Wang ◽

Jingjing Luo ◽

Xin Liu ◽

Bin Li ◽

...

Keyword(s):

Quantum Dots ◽

Graphene Oxide ◽

Energy Transfer ◽

Dual Emission ◽

Doped Quantum Dots

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Synthesis and Surface Modification of Biocompatible Water Soluble Core-Shell Quantum Dots

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.879.184 ◽

2014 ◽

Vol 879 ◽

pp. 184-190 ◽

Cited By ~ 1

Author(s):

Samsulida Abd. Rahman ◽

Nurhayati Ariffin ◽

Nor Azah Yusof ◽

Jaafar Abdullah ◽

Zuhana Ahmad Zubir ◽

...

Keyword(s):

Quantum Dots ◽

Average Particle Size ◽

Fluorescence Emission ◽

Water Soluble ◽

Average Particle ◽

Silar Method ◽

Mercaptosuccinic Acid ◽

Transmission Electron ◽

Layer Adsorption ◽

Capping Ligands

In this study, the applications of CdSe/ZnS quantum dots (QDs) and its role in advanced sensings has been explored. The CdSe/ZnS was synthesized by using hot injection method with the shell ZnS layer was made using successive ionic layer adsorption and reaction (SILAR) method. The morphology of the CdSe/ZnS QDs was studied using Transmission Electron Microscope (TEM) and the average particle size was in 10-12 nm range. The prepared QDs were optically characterized using spectrofluorescence and strong emission was observed at 620 nm. Comparison of the fluorescence emissions of CdSe/ZnS capped with various capping ligands such as L-cysteine, thioglycolic acid (TGA), mercaptopropionic acid (MPA), mercaptosuccinic acid (MSA) and mercaptoundecanoic acid (MUA) were studied. The CdSe/ZnS capped with TGA gave the strongest fluorescence emission compared to others.

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